e39 electrical problems

i have recently installed an amp and subwoofer and the amp wont shut off when the car is turned off causing the battery to drain. i have had to remove the fuse. also around the same time. a whizzing noise is heard each time the radio is turned on or off even with the amp disconnected. and once after the car was shut off and keys out the left blinker light remained on. can anyone offer any help on what is causing this and how i can remedy this matter?

make sure that u have properly hooked up the remote wire on to the amp so the amp can read that the car is off and for the whizzing sound u might have a crossed wire behind the radio email me with how u hooked up your wires and ill be able to tell u if it was properly done,